Taiwan, officially the Republic of China, is a state in East Asia. Originally based in mainland China, the Republic of China now governs the island of Taiwan, which makes up over 99% of its territory, as well as Penghu, Kinmen, Matsu, and other minor islands. Neighboring states include the People's Republic of China to the west, Japan to the east and northeast, and the Philippines to the south. Taipei is the seat of the central government. New Taipei, encompassing the metropolitan area surrounding Taipei proper, is the most populous city.

Constitutionally, the ROC government has claimed sovereignty over all of "China", in a definition that includes mainland China and Outer Mongolia, as well as Taiwan, but has not made retaking mainland China a political goal since 1992. However, the government's stance on defining its political position largely depends on which political coalition is in charge. Meanwhile, the PRC also asserts itself to be the sole legal representation of China and claims Taiwan as its 23rd province to be under its sovereignty, denying the status and existence of ROC as a sovereign state. The PRC has threatened the use of military force as a response to any formal declaration of Taiwanese independence, or if it deems peaceful reunification no longer possible. Cross-strait relations as well as issues of national identity within the country are important factors in Taiwanese politics and a cause of social and political division among political parties and their respective supporters.